Fluid control devices



Feb. 14, 1967 R. B. WILKERSON 3,304,049

FLUID CONTROL DEVICES Original Filed Jan. 9, 1963 2 Sheets-Sheet 1lNVENTOR. ROBERT 5. W/L/(ERSON,

ATTORNEY- Feb. 14, 1967 R. B. WILKERSON 3,304,049

FLUID CONTROL DEVICES Original Filed Jan. 9, 1963 2 Sheets-Sheet 2lNVENTOl-P. ROBERT B. W/LKERso/v,

ATTORNEY.

United States Patent 3,304,049 FLUID CONTROL DEVICES Robert B.Wilkerson, Bloomington, Ill., assignor to General Electric Company, acorporation of New York Original application Jan. 9, 1963, Ser. No.250,448. Divided and this application Sept. 1, 1965, Ser. No.

3 Claims. Cl. 251-139 This is a division of application Serial No.250,448, filed January 9, 1963.

This invention relates to fluid control devices and has particularrelation to fluid amplifiers.

Fluid amplifiers are currently finding wide application in variousfields due primarily to their reliability, temperature insensitivity,shock resistance, and ease of fabrication. These devices may be employedas digital and analog computing elements and also can be utilized aspower devices to operate pistons and the like. Fluid amplifiers may beoperated equally as well as pneumatic devices employing a compressiblefluid, such as gas or air, or as hydraulic devices utilizingincompressible fluids, such as water or oil.

Two basic types of fluid amplifiers exist, the first being commonlyreferred to as the momentum exchange type wherein a main or power fluidjet is deflected by one or more control jets directed laterally at thepower jet. The power jet is normally directed midway between two fluidreceivers and is deflected relative to the receiver by an amountproportional to the net sideways momentum of the control jets. Thisdevice is accordingly sometimes referred to as a proportional or analogdevice.

The second type of amplifier is generally known as a boundary layer orCoanda effect device. In this latter device the power jet is deflectedby the action of side walls of an interaction chamber which are shapedin such a way that the power jet will attach to one or the other of theside walls but not to both of the side walls. This operation is broughtabout by the entrainment action of the power jet wherein the power jettends to entrain air trapped between it and an adjacent side wall, theentrainment becoming more effective as the power jet approaches theadjacent side wall. This type of device is basically a two positiondevice and for this reason is referred to as a digital device.

Both the analog and digital type of amplifier can be employed as powerdevices to drive comparatively large loads such as spool type valves andthe like which are operatively connected to the fluid receivers. In suchpower applications it is very desirable that the fluid control device beof inexpensive and compact construction with a minimum number of partswhich are readily fabricated. It is also advantageous that the load beoperated in response to application of a very low level input signal tothe device, such as the electrical output signal from an electronic ormagnetic static control system. It is further desirable in such devicesthat provision be made for supplying the fluid amplifier with fluidderived from the working fluid introduced into the load cylinder so thatthe device is self-energized.

It is therefore a primary object of the present invention to provide anovel and improved fluid control device which is of compact andinexpensive construction employing a minimum number of parts.

It is another object of the invention to provide a novel and improvedfluid control device which is self-energized and which is designed foroperating comparatively large loads.

It is a further object of the invention to provide a novel and improvedfluid control device capable of operating comparatively large loads inresponse to very low level input signals.

3,304,049 Patented Feb. 14, 1967 It is still another object of theinvention to provide a novel and improved fluid control device designedfor operating a load within a load cylinder and including a fluidamplifier which is supplied with pressure fluid through the loadcylinder from working fluid introduced into the load cylinder.

It is a still further object of the invention to provide novel andimproved input means for controlling the position of a fluid jet in afluid amplifier.

In carrying out the invention in one form a fluid control device isprovided designed primarily for employment as a power device to operatecomparatively large loads such as reciprocable valves. The devicesincludes a fluid amplifier section having a nozzle for generating :a jetof fluid, such as air, the axis of the nozzle extending along a pathmidway between two fluid receiving load passages. The fluid amplifier ispreferably of the boundary layer type and includes a pair of controlchambers for receiving pressure fluid for controlling attachment anddetachment of the jet relative to a pair of side walls of an interactionchamber located between the nozzle and the fluid receiving passages.

The device additionally includes a valve section including a valvecylinder containing a reciprocable spool valve for controlling the flowof pressure fluid between a pair of supply and output passagescommunicating with the cylinder. The cylinder is in communication withan auxiliary passage which contains a pair of opposed adjustable valvesand which is connected in communication with the jet nozzle and with thecontrol chambers of the fluid amplifier. With this arrangement thedevice is self energized, the fluid for the control chambers and thefluid for the power jet of the fluid amplifier being furnished by theworking fluid supplied to the valve cylinder.

In a pneumatic device constructed according to the present invention andemploying air as the fluid, the control chambers of the fluid amplifierare connected to communicate with the atmosphere, and for this purpose acover section is provided containing control passages which connect thecontrol chambers of the fluid amplifier to atmosphere, the cover sectionoverlying one side of the fluid amplifier section which is sandwichedbetween the cover section and the valve section. If desired, these threesections may be independent of one another and may be detachably securedto one another in any suitable manner. Control of the device i readilyobtained by opening and restricting the control passages in the coversection to vary the fluid pressure in the control chambers of the fluidamplifier. This way be accomplished by a variety of arrangements.

According to a further aspect of the 'invention con-' trol of the deviceis effected by operation of means having a part which is disposedadjacent one or more of the control passages in the cover section andwhich is movable to open and restrict the control passage. The means mayassume various forms and in one form comprises a relay having a magneticcore containing a bleed orifice which communicates with one of thecontrol passages and which is opened and closed in response to movementof an armature resulting from energization and deenergization of a coil.By such arrangement the spool valve is reciprocated in response to avery low level of energization of the relay coil.

Other objects and advantages of the invention will become apparent fromthe following description taken in conjunction with the accompanyingdrawings in which:

FIG. 1 is a diagrammatic view in perspective illustrating a fluidcontrol device constructed according to the invention;

FIG. 2 is a diagrammatic vie-w of the device of FIG. 1 flattened out ina common plane showing particularly the fluid connections in the device;

FIG. 3 is a diagrammatic view showing in particular one form of relayfor controlling operation of the device of FIGS. 1 and 2;.

FIG. 4 is a diagrammatic view in perspective showing a solenoidarrangement for controlling operation of the device of FIGS. 1 and 2;

FIG. 5 is an exploded view in perspective showing parts of one of thesolenoids of FIG. 4;

FIG. 6 is a viewin top plan showing a solenoid arrangement diflerentthan that shown in FIGS. 4 and 5 and employing a singlecoil; and

FIG. 7 is a view similar to FIG. 6 showing the device of FIG. 6 with adouble coil arrangement.

Referring now to the drawings there is illustrated in FIG. 1 anembodiment of the invention in the form of a boundary layer type fluidcontrol device consisting of three sections including a fluid amplifiersection 10, a valve section 11, and a cover section 12, the section 10'being sandwiched between the sections 11 and 12. The sections 10-12 maybe separately formed and detachably secured to each other in anysuitable manner, or the fluid amplifier 10 may be formed as an integralpart of either the valve section 11 or the cover section 12.

In general, pressure fluid applied to the amplifier section 10 operatesa suitable load device in the valve section 11, such as a reciprocalvalve 13, in response to selective opening and restriction of controlinput conduits or passages 14 and 15 located in the cover section 12 andopening to atmosphere. The fluid employed in the device may be of anysuitable character, a compressible fluid, such as air or gas, beingcapable of use to provide a penumatic device, or an incompressiblefluid, such as oil or water, being also usable to provide a hydraulicdevice. Inthe illustrated embodiment it will be assumed that the fluidconstitutes air to provide a pneumatic control device.

The present invention is applicable to control devices employing fluidamplifiers of either the boundary layer type or the momentum exchangetype, and the invention will :be described with reference to a controldevice utilizing a boundary layer type fluid amplifier. In theillustrated embodiment the amplifier section 10 includes a plate 16formed of any suitable material, such as metal, plastic or the like,which is slotted in a unique configuration to provide the boundary layeramplifier. The plate 16 is formed with a main pressure fluid receivingopening 17 having a restricted neck 18 defining a nozzle from whichissues a jet of fluid, the fluid being derived from a pressure fluidsource and applied to the opening 17 in a manner more fully describedhereinafter.

In order to control the direction of flow of the jet the plate 16 isformed with a pair of control chambers 19 and 20 opening at areasadjacent the nozzle 18 and on opposite sides of the axis of the nozzle.The chambers 19 and 20 are adapted to receive pressure fluid from anysuitable source which cooperates with boundary layer regions adjacentside walls 21 and 22 of an interaction chamber 23 to control deflectionof the jet issuing from the nozzle 18.

As is understood in the art, the fluid jet issuing from the nozzle 18normally is attached to one or the other of the side walls 21 and 22 inthe absence of control fluid pressure applied to the chambers 19 and 20,and will enter one of two fluid receiving passages 24 and 25 which areformed in the plate 16 and which are connected in communication with avalve cylinder 29 formed in the valve section 11 as will presentlyappear. Let is be assumed that the jet is initially attached to the sidewall 21. If fluid pressure is introduced into the control chamber 19 andis increased above a certain value, then the jet will be detached fromthe wall 21 and will be flipped into attachment with the wall 22, thejet remaining in the attached condition even after removal of fluidpressure from the chamber 19. To detach the jet from the wall 22 fluidpressure must be introduced into the chamber 20' and increased above acertain level at which time the jet will detach from the wall 22 andwill flip into attachment with the wall 21. The above describedattaching and detaching actions of the jet occur very rapidly inresponse to very small fluid pressures in chambers 19 and 20.

In the illustrated embodiment the valve section 11 is in the form of arectangular block 30 of any suitable material, such as plastic, metal orthe like and includes therein a plurality of passages for fluid. One ofthe passages in the block 30 constitutes the valve cylinder 29 whichcontains the valve 13, the valve 13 being reciprocal in the cylinder 29between a pair of combination plugs and stops 31 adjustably positionedin the ends of cylinder 29. The block 30 is formed with a pair of spacedparallel passages 32 and 33 which communicate with the cylinder 29 andwhich open at one side of the block 30 to cornmunicate with the loadpassages 24 and 25 formed in the amplifier plate 16 when the plate 16and block 30 are operatively secured together. The valve 13 includes apair of spaced lands 34 and 35 located between the passages 32 and 33for any position of the valve and connected by a reduced central section36. The lands 34 and 35 appear as piston loads to fluid entering thecylinder 29 through the passages 32 and 33 and the valve 13 will bedisplaced in a direction dependent upon which of the passages 32 and 33is receiving fluid from the amplifier section 10.

The valve 13 controls the flow of fluid between a supply passage 37 andan output passage 38 formed in the block 30 in spaced parallel relationto extend between the cylinder 29 and one side of the block 30. Supplyand output conduits 39 and 40 are attached to the passages 37 and 38 inany suitable manner and fluid under pressure is conducted through thesupply conduit 39 from a suitable source of pressure fluid (not shown).The passages 37 and 38 are conveniently formed with internal threads tothreadably receive the conduits 39 and 40.

. As best shown in FIG. 2 and lands 34 and 35 of the valve 13 are spacedfrom the adjacent open ends of the passages 37 and 38 when the valve isin its right-hand position which results when fluid flows into thecylinder 29 through the passage 32 from the load passage 24 of theamplifier 10. For this condition fluid under pressure flows through theconduit 39, the passage 37, the cylinder 29, the passage 38 and theconduit 40 to a suitable load device (not shown). When the jet of fluidissuing from nozzle 18 of the amplifier 10 is deflected to enter theload passage 25, the valve 13 will be shifted toward the left from itsposition illustrated in FIG. 2 so that the land 34 will engage the stop31 to position the land 35 over the open end of the output passage 38.For this condition fluid under pressure flowing through the conduit 39is prevented from flowing out the passage 38 and the conduit 40.

As previously stated fluid under pressure is applied to the opening 17and to the control chambers 19 and 20 of the amplifier 10 and thepressure of fluid applied to chambers 19 and 20 is employed to controlthe direction of deflection of the fluid jet issuing from the nozzle 18.Fluid applied to the opening 17 and to the chambers 19 and 20 may besupplied from any suitable source of pressure fluid, and in the presentinvention the control device is self-energized wherein the fluid appliedto the opening 17 and to the chambers 19 and 20 is derived from thefluid supplied to the cylinder 29. In order to accomplish this desirablearrangement theblock 30 is formed with a plurality of passages whichconduct fluid from the cylinder 29 to the opening 17 and to the controlchambers 19 and 20. In the embodiment of FIG. 1 the block 30 is formedwith an elongated passage 44 parallel to the cylinder 29 and including acentral restricted portion 45 connected to the cylinder 29 by a passage46, and a pair of enlarged end portions 47 and 48 which open at oppositeends of the block 30. The block includes also three spaced parallelpassages 49, 50 and 51 extending generally perpendicular to the passageportions 45, 47 and 48,

the passages 49 and 51 communicating with the passage portions 47 and 48and opening at one side of the block 30, and the passage 50communicating with the passage portion 45 and opening at the same sideof the block 30. When the block 30 and the amplifier are operativelypositioned, the passages 49 and 51 open respectively into the controlchambers 19 and 20 and the passage 50 opens into the opening 17 of theplate 16.

It is observed that with the above-described arrangement fluid underpressure is continuously supplied to the control chambers 19 and 20 andto the opening 17 of the plate 16 from the supply conduit 39 in theblock 30. In order to permit adjustment of the fluid pressure in thecontrol chambers 19 and 20 and in the interaction chamber 23 a pair ofadjustable valves 52 and 53 shown in the form of needle type valves arethreadably received within the end passages 47 and 48 to permitvariation of the amount of fluid flowing from the central passage 45through the passages 49 and 51 and thence to the control chambers 19 and20. For example, if the valve 53 is screwed into the block 30 by adistance greater than the I valve 52, a smaller amount of fluid ispermitted to flow through the passage 51 than through the passage 49whereby the pressure of fluid applied to the control chamber 19 isgreater than that applied to the chamber 20. This results in attachmentof the jet of fluid issuing from nozzle 18 to the side wall 22 wherebythe jet passes through the load passage 25 and through the passage 33into the cylinder 29 to displace the valve 13 toward the left as viewedin FIG. 2. As will presently appear, adjustment of the fluid pressure inchamber 23 is controllable by arrangements other than the valves 52 and53 and the passages 49 and 51.

In order to permit venting of fluid from the device a pair of spacedparallel vent passages 55 and 56 are provided in the cover section 12each of which opens at opposite sides of the cover section. When thecover section 12 and the amplifier plate 16 are operatively positioned,the open ends of the vent passages 55 and 56 adjacent the plate 16 areplaced in communication with the load passages 24 and 25 in theillustrated embodiment and serve to conduct fluid to atmosphere from theload passages in the event that the cylinder cannot receive the fluidsupplied to it causing fluid to back up in the load passages. The ventpassages may be located in other regions of the amplifier plate 16 thanthose shown. For example, the vent passages may be located in theinteraction chamber 23. In addition, the vent passages 55 and 56 may beutilized to control fluid pressure in the chamber 23. For this purposethe valves 52 and 53 and the passages 49 and 51 may be omitted, andmeans provided to controllably restrict the vent passages 55 and 56. Insuch an arrangement the end portions 42 and 48 of the passage 44 wouldbe plugged and fluid pressure would be applied to the passages 14 and15.

The control passages 14 and are provided for the purpose of permittingcontrol of the pressure of fluid in the control chambers 19 and 20, andto therefore permit control of the position of the jet issuing from thenozzle '18. Pressure of fluid in the chambers 19 and may be controlledeither by opening normally closed or restricted passages 14 and 15, byclosing or restricting normally open passages 14 and 15, or byintroducing pressure fluid into the passages 14 and 15. For example, letit be assumed that both passages 14 and 15 are normally open and thatthe valve 52 is withdrawn from the passage 47 to a greater extent thanthe valve 43 so that pressure of fluid in control chamber 19 is greaterthan that in control chamber 20. With this assumption the fluid jetissuing from nozzle 18 is attached to the side wall 22 to enter loadpassage and displace the valve 13 toward the left as viewed in FIG. 2.If the control passage 15 is now closed, or if pressure fluid isintroduced into the passage 15, pressure of fluid in the chamber 20 willincrease above pressure of fluid in chamber 19 with the result that thejet 6 will be detached from side wall 22 and will be flipped intoattachment with side wall 21 to effect displacement of the valve 13 toits illustrated position. If the control passage 15 is subsequentlyopened, the jet will detach from the side Wall 21 and return to the sidewall 22 to displace the valve 13 toward the left as viewed in FIG. 2.

Other operational modes of the fluid control device are possible. Forexample, by initially providing substantially equal pressures of fluidin the control chambers 19 and 20 the device can be made bistable. Toillustrate this, assume that the pressures of the control chambers 19and 20 are equalized and that both of the control passages 14 and 15 areopen. If the passage 14 is now closed, pressure of fluid in chamber 19will increase and the jet will flip to the wall 22 if previouslyattached to wall 21, and will enter the load passage 25. Due to thepressure conditions in the interaction chamber 23, opening of thepassage 14 will result in the jet remaining attached to the side wall 22until the other passage 15 is closed. When the passage 15 is closed, thejet will fiip to the wall 21 and will enter the load passage 24. Indevices which employ such bistable operation the needle valves 52 and 53can be eliminated since they are not needed to effect an unbalance ofpressure in the chambers 19 and 20.

The above methods of control are referred to as normally openoperational modes of the device wherein jet deflection is effected byclosing normally open passages 14 and 15, and it is appreciated that thedevice can be operated under normally closed conditions as well whereinjet deflection is eflected by opening normally closed passages 14 and15. To illustrate this, assume that fluid pressures in the controlchambers 19 and 20 are equalized to provide bistable operation, and thatthe passages 14 and 15 are normally closed. If the passage 14 is opened,pressure of fluid in chamber 19 will be reduced below that in chamber 20with the result that the jet will flip to the side wall 21 if previouslyattached to wall 22 and will enter the passage 24. The jet will remainin such position even though the passage 14 is subsequently closed untilthe passage 15 is opened at which time the jet will flip to the sidewall 22.

According to the invention, improved means are provided for controllablyrestricting the passages 14 and 15 to control the position of the jet inthe plate 16. In one aspect of the present invention this isaccomplished by electrically operated means requiring a very low levelelectrical input to effect displacement of the valve 13. Referring nowto FIG. 3 there is illustrated one embodiment of the invention in theform of a relay 60 mounted on the fluid control device and including amagnetic armature 61 movable relative to a magnetic core 62 in responseto energization of an electroconductive coil 63 surrounding the core 62for controllably restricting a selected one of the control passages 14and 15. For this purpose a retaining screw 64 is screwed into a selectedone of the passages 14 and 15, the screw 64 being formed with an opening65 extending throughout its length which communicates with an opening 66which is formed in the magnetic core 62 and which threadably receivesthe screw 64. The opening 66 terminates at its upper end in a smallbleeder orifice 67 adapted to be opened and closed by movement of thearmature 61 relative to the core.

The armature 61 is pivotally supported by a supporting frame 68 and isbiased to an elevated position illustrated in FIG. 3 wherein the orifice67 is open by means of a bias spring 70 which also urges a contactcarrier 71 toward the left as viewed in FIG. 3. According to a furtheraspect of the invention the contact carrier 71 supports a movablecontact 72 which moves between a pair of spaced fixed contacts 73 inresponse to movements of the armature 61 for effecting an additionalcontrol operation. The coil 63 of the relay 60 may be energized from anysuitable voltage source. For example, the relay 60 described herein canbe energized from the output circuits of magnetic or semiconductorstatic control systems through intermediate amplifiers or relays. A verylow level input, such as approximately 50 milli- Watts, is all that isrequired to move the armature 61 and effect displacement of the valve13. It can be appreciated that to provide bistable operation, anotherrelay similar to the relay 60 must be provided to control a bleederorifice in communication with the passage 15.-

Referring now to FIGS. 4 and there is illustrated a different controlarrangement than that shown in FIG. 3. In FIG. 4 there is shown a pairof similar solenoids 75 to provide bistable operation with each of thesolenoids 75 being of different construction than the relay 60 of FIG.3. Each solenoid 75 includes an elongated cylindrical core 76 attachedat one end to an L-shaped bracket 77 having an opening 78 through whichextends a nozzle 79 into threaded engagement with one of the passages 14and 15. A nut 80 is threaded on the nozzle 79 to retain the bracket 77against the upper surface of the cover section 12.

The solenoid 75 includes a coil 81 adapted to be slipped on to the core76 and retained thereon by means of a nut 82 which is threaded on thethreaded end of the core 76. In order to open and close the passage 14or 15 to control deflection of the fluid jet in the amplifier there isprovided a generally L-shaped thin magnetic reed 83 formed of springmaterial and having a short arm 84 with an opening 85 therein adapted toreceive the core 76, the long arm 86 of the reed extending generallyparallel to the core to overlie the end of the nozzle 79 when the reedis operatively positioned on the core. The long arm 86 of the reed isnormally spaced from the end of the nozzle 79 so that the nozzle 79 andthe associated passage 14 or are open, and is deflected downwardlyagainst the nozzle 79 to close the nozzle and the associated passage inresponse to energization of the coil 81. When the coil 81 issubsequently deenergized, the arm 86 of the reed will return to itsnormal spaced position.

Referring now to FIGS. 6 and 7 an electromagnetic controller is providedwhich differs from the relay 60 and the solenoid 75 previouslydescribed. The device of FIGS. 6 and 7 is represented generally by thenumeral 90 and is designed for employment with control devices which arearranged for bistable operation. As will presently appear, the device 90employs a single magnetic reed adapted for single coil operation oneither side (FIG. 6), or double coil operation (FIG. 7).

The device 90 includes a flat plate 91 adapted to be secured to theouter surface of the cover section 12 and including a pair of opposedupstanding brackets 92 and 93. Intermediate the brackets 92 and 93 are apair of generally L-sh-aped nozzles 94 and 95 having first open endsextending through the plate 91 into the passages 14 and 15 respectively,and having second open ends in spaced confronting relation on oppositesides of the end of a long arm 96 of an L-shaped magnetic reed 97 havingalso a short arm 98. The reed 97 is secured to the bracket 93 by meansof a screw 99 (FIG. 7) which extends through openings in the bracket 93and in the short arm 98 into threaded engagement with an opening 100formed in a cylindrical magnetic core 101. A coil 102 is mounted on abobbin 103 which surrounds the core 101 and which mounts a magnetic pole104 adjacent the outer end of the core 101 when the bobbin isoperatively positioned.

Provision is made for adjusting the reed 97 so that the long arm 96thereof closes a selected one of the nozzles 94 and or is centeredmidway between the two nozzles when the coil 102 is deenergized. Lateraladjustment of the long arm 96 of the reed is readily accomplished byrotating a screw 105 which is threaded into an opening of the bracket 93and which extends into engagement with the joint between the arms 96 and98 of the reed.

In FIG. 7 the double coil arrangement is shown including a coil 110, abobbin 111, a magnetic core 112 and a magnetic pole 113 corresponding tothe items 101-104 previously described. In this double coil arrangementthe arm 96 of the reed 97 is adjusted by rotation of the screw 105 sothat arm 96 is in a normal position midway between the nozzles 94 and 95when both of the coils 102 and are deenergized.

While I have shown and described particular embodiments of my invention,it will be obvious to those skilled in the art that various changes andmodifications may 'be made without departing from my invention in itsbroader aspects and I, therefore, intend in the appended claims to coverall such changes and modifications as fall within the true spirit andscope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A self-mounting fluid control device for controlling the flow offluid from a passage comprising an elongated retaining member having anopening extending therethrough, said retaining member being adapted forreception within the passage to be supported thereby, a generallyL-s'haped support frame having a pair of legs, one of said legs havingan aperture therein through which passes said retaining member, amagnetic core having an opening extending therethrough, said openingbeing formed as a bleeder orifice at one end and receiving saidretaining member at the other end so that said core is fixedly supportedby said retaining member, a coil surrounding said core, a magneticarmature pivotally supported at the free end of the other of said legsof said support frame which other leg extends generally parallel to saidcore, and resilient means biasing said armature with respect to saidsupport frame whereby said armature is normally biased to uncover saidorifice, and is pivoted to cover said orifice when said coil isenergized to stop the flow of fluid from the passage through saidorifice.

2. The self-mounting fluid control device defined in claim 1 whereinsaid retaining member is cylindrical and is externally threaded, and thepassage and said opening in said magnetic core are cylindrical andthreaded, whereby said core is threaded onto said retaining member andsaid retaining member is threaded into the passage to mount said fluidcontrol device.

3. The self-mounting fluid control device defined in claim 1 whereinsaid armature supports a movable contact in proximity to a fixedcontact, such that energization and deenergization of said coil causessaid movable contact to be moved between open and closed positionsrelative to the fixed contact.

References Cited by the Examiner UNITED STATES PATENTS 4/1907 Dempster25l139 X 7/1958 Penther 251-141 X FOREIGN PATENTS 728,906 11/ 1942Germany.

1. A SELF-MOUNTING FLUID CONTROL DEVICE FOR CONTROLLING THE FLOW OFFLUID FROM A PASSAGE COMPRISING AN ELONGATED RETAINING MEMBER HAVING ANOPENING EXTENDING THERETHROUGH, SAID RETAINING MEMBER BEING ADAPTED FORRECEPTION WITHIN THE PASSAGE TO BE SUPPORTED THEREBY, A GENERALLYL-SHAPED SUPPORT FRAME HAVING A PAIR OF LEGS, ONE OF SAID LEGS HAVING ANAPERTURE THEREIN THROUGH WHICH PASSES SAID RETAINING MEMBER, A MAGNETICCORE HAVING AN OPENING EXTENDING THERETHROUGH, SAID OPENING BEING FORMEDAS A BLEEDER ORIFICE AT ONE END AND RECEIVING SAID RETAINING MEMBER ATTHE OTHER END SO THAT SAID CORE IS FIXEDLY SUPPORTED BY SAID RETAININGMEMBER, A COIL SURROUNDING SAID CORE, A MAGNETIC ARMATURE PIVOTALLYSUPPORTED AT THE FREE END OF THE OTHER OF SAID LEGS OF SAID SUPPORTFRAME WHICH OTHER LEG EXTENDS GENERALLY PARALLEL TO SAID CORE, ANDRESILIENT MEANS BIASING SAID ARMATURE WITH RESPECT TO SAID SUPPORT FRAMEWHEREBY SAID ARMATURE IS NORMALLY BIASED TO UNCOVER SAID ORIFICE, AND ISPIVOTED TO COVER SAID ORIFICE WHEN SAID COIL IS ENERGIZED TO STOP THEFLOW OF FLUID FROM THE PASSAGE THROUGH SAID ORIFICE.